When asked to identify the invention that had the most profound impact on society over the last few centuries, most people would identify remarkable advances such as the electric light, the airplane, the telephone or the Internet. The lowly flush toilet does not come immediately to mind. Yet, the flush toilet and indoor plumbing can be said to have truly changed the world.
Medieval castles were often built with “garderobes”—private bathrooms that exhausted waste downward through a pipe into a cesspool below the castle walls. Wealthy upper class people made use of chamber pots that their servants emptied by hand. Common folk generally used outhouses for their sanitary needs, but outhouses presented all sorts of inconveniences not the least of which was the need to venture out into the cold. More significantly, unsanitary handling of human waste often spread deadly diseases—especially in cities and other areas of high population density.
Indoor plumbing and the siphon-based flush toilet eliminated all of these problems. Credit for the basic flush toilet is usually given to Sir John Harington, who lived in 16th century England. Harington reportedly came up with the idea of constructing a chamber pot that used running water (hydraulics) to remove waste and carry it away. Others later came up with improvements such as a water-filled trap beneath the bowl to prevent sewer gas from entering from the waste pipe and making use of a siphoning effect to rapidly evacuate the toilet bowl.
FIGS. 1, 2 & 2A show an exemplary illustrative non-limiting modern (prior art) toilet 50 comprising a tank 52 and a bowl 54. The tank 52 holds a quantity of water W. Pulling on the flush handle 56 causes a lever 58 to lift a chain 60, which in turn raises a “flapper” 62 at the bottom of the tank 52. Flapper 62 is a kind of valve that flaps open and closed. When chain 60 raises flapper 62 off of a flush valve seat, water W from the tank 52 rushes downward through an opening into the bowl 54. This inrush of water flows through rim holes 55a and siphon hole 55b (see FIG. 2A). This water inrush increases the water pressure within the bowl, forcing water through exhaust port 63 and past vapor trap 55c beneath the bowl and down into waste pipe 57. This flow of water and waste into the waste pipe 57 creates a strong siphon that evacuates the bowl through exhaust port 63, producing the characteristic flushing sound familiar to most people. In most toilets, the bowl 54 is molded so that the water enters the rim, and some of it drains out through holes in the rim. A good portion of the water flows down to a larger hole at the bottom of the bowl as shown in FIG. 2A. This hole is known as the siphon jet. It releases most of the water directly into the siphon tube. Because all of the water in the bowl enters the tank in a very short time (e.g., three seconds), it is enough to fill and produce the siphon effect, and all of the water and waste in the bowl is sucked out.
When nearly all of the water has escaped from the tank 52, the flapper 62 descends back down to its original position as shown in FIG. 2, once again sealing the water passage between the tank and the bowl 54. Fresh tap water flowing into the tank 52 through a fill valve 66 from an inlet pipe 64 begins to fill the tank. A float 112 rises with the rising water level. When the float 112 reaches a preset level, it closes the fill valve 66 and water ceases to flow into the tank 52. The toilet 50 is now ready for another flush.
While toilets are generally reliable, they can malfunction from time to time. Perhaps the most common malfunction is when the flapper 62 remains open, leaks or is misaligned, causing the toilet to “run.” A stuck-open flapper 62 can waste a lot of water. This can be a serious problem, especially in cases of water shortages or droughts. Sometimes the fix is as simple as jiggling the flush handle 56. Other times, it is necessary to replace the flapper 62. It is often possible to detect the flapper 62's failure to close by listening for water running continuously into the tank 52. Sometimes, however, people are not home to hear the water running. People who are hearing impaired may not be able to hear water running. Hundreds of gallons of water can be wasted in this way in a relatively short time. Some readily available water authority surveys estimate that of the approximately 240,000,000+ toilets in the United States, as many as one in five may be leaking to some extent.
A running toilet can waste a lot of water but usually does not present health hazards. An overflowing toilet, on the other hand, can be a serious household hygiene disaster—as anyone who has ever had to clean up the consequences knows very well. Watching water rise to the top edge of a toilet bowl is a fearful experience. Overflowing toilet bowls can spread germs and disease, cause structural damage to homes and businesses, contribute to toxic mold, and cause other bad effects.
FIG. 3 shows a clogged toilet situation. When debris (e.g., a child's toy, excess quantities of toilet paper, etc.) blocks the toilet exhaust port 63 or further down waste pipe 57, flushing the toilet does not cause the bowl 54 to evacuate. Instead, the water level within bowl 54 continues to rise as water from the tank 52 rushes downward into the bowl. In many instances, the water will stop rising before the toilet overflows. This is because most toilet bowls 54 are designed to hold the entire contents of the tank 52 without overflowing—but only if the water in the tank falls low enough to allow the flapper 62 to seat so as to prevent further water from flowing into the bowl 54. Overflow can occur with just a single flush when a blocked siphon hole (see FIG. 2A) prevents the rapid evacuation of the water in the tank 52 while the fill valve 66 is open.
Toilets can also overflow if the water level in the bowl 54 starts out higher than normal when the toilet is flushed. As FIG. 4 shows, when a toilet bowl 54 is clogged so that a flush doesn't flush the bowl's contents away, some people will flush the toilet a second time in the hope that the additional water will push the bowl contents down through the outlet pipe 63. Additional flushing rarely clears the clog, but can easily cause a toilet bowl to overflow.
Parents should warn their children that when the water level in a toilet bowl is higher than normal, the toilet should not be flushed again. Unfortunately, it is common for children and others who do not know better to flush a toilet repeatedly in the hope that repeated flushing will eliminate the blockage.
Many in the past have tried to use technology to prevent toilets from overflowing or wasting water. Generally speaking, the solutions that exist to date are unsatisfactory. Some are ineffective, others are too expensive, and others are too difficult to install. One existing solution involves placing an electronic valve in the fluid fill line 64. Such installation requires plumbing knowledge. Other known solutions involve special toilet designs that provide overflow plumbing. None of these approaches has been widely adopted, so the troublesome problems of toilet overflow and water waste still exist. It is a significant challenge to solve these problems for the large number of toilets already installed in millions of homes and businesses.
What is needed is a simple, yet effective, reliable, relatively inexpensive solution that can be used with both new and already existing toilets and which can be easily installed and operated with high reliability.
The exemplary illustrative non-limiting technology described herein provides a new and useful single self-contained apparatus, located completely within the toilet tank, which can detect and prevent a toilet overflow and/or limit the unnecessary waste of water through a leaking flapper.
Exemplary illustrative non-limiting technology is for use with a toilet tank fill valve comprising a float and a water valve that operates in response to float position. A protective cap at least in part covers the water valve. As usual, the water valve selectively admits water into the toilet tank. An improved system and method for use with such a fill valve compatibly mounts on the fill valve protective cap and conditionally interferes with or overrides the operation of the toilet tank fill valve.
Exemplary illustrative non-limiting steps include removing the toilet tank lid to provide access to the toilet tank fill valve therewithin, manually snapping an assembly onto said fill valve cap, and automatically and conditionally actuating the assembly to cause the assembly to selectively interfere with the operation of said toilet tank fill valve e.g. thereby preventing a further toilet flush.
A further exemplary illustrative non-limiting device for use with a toilet tank fill valve assembly comprises an attaching structure for manual attachment to the fill valve cap. A control mechanism supported by an attaching structure acts to conditionally interfere with the operation of the toilet tank fill valve assembly to prevent overflows and/or water waste.
Further exemplary illustrative non-limiting features and/or advantages include:                An attaching structure that can be manually attached to the fill valve without use of specialized tools.        A control mechanism comprising an arm member that, in response to sensed water flow within the tank, conditionally raises the float instead of relying (just) on rising water level to raise the float.        An attaching structure comprising a flexible structure that snaps onto the existing fill valve protective cap or, alternatively, replaces the cap.        Some designs require no disassembly of or modification to a conventional fill valve design.        An attaching structure that comprises a dome element that can snap over a conventional fill valve protective cap.        An attaching structure that includes fingers that snap over the cap.        An attaching structure that does not interfere or impede the normal operation of a toilet tank fill valve until a control mechanism is activated to cause conditional interference.        An electrical actuator that actuates a control mechanism to conditionally interfere with the operation of a toilet tank fill valve assembly in response to an electrical control signal.        A control member comprising a member that additionally retains the float of a toilet fill valve in an uppermost position.        A control mechanism that includes a filament, a rod, an electric motor, hydraulic piston, hydraulic-activated lever, and/or a solenoid.        An attaching mechanism that includes a portion for engaging a cylindrical surface of said cap, said engaging portion having a dimension of approximately 50 cm in diameter and 25 cm in height.        A device that is dimensioned so as not to interfere with typical placement of a toilet tank lid.        A device that comprises materials designed to be substantially impervious to degradation by water and/or toilet tank contaminants.        An attaching structure that can be non-destructively removed from the protective cap.        An attaching structure that can be manually removed from the fill valve.        No direct connection between said device and a flush handle of the toilet.        A control mechanism that is resettable to cease interfering with fill valve operation.        A control mechanism that is resettable manually or automatically.        A practical cost-effective product that is virtually impervious to the harsh environment common to toilet tanks, reliable in operation, unaffected by changes in fluid viscosity and conductivity, simple in construction, and inexpensive to manufacture and implement.        Universal application to the many different types of toilets and their varying tank sizes.        Ideally adaptable and installed without the end-user being forced to make any modifications.        Ruggedly and compactly designed in a way that will allow it to be installed inside the toilet tank itself.        A layperson should be able to install it in a few minutes, without the use of any tools or the user being forced to touch or handle any part of the toilet, except for the toilet tank lid, with simple instructions.        A single-piece system that determines when a toilet bowl overflow is about to happen and prevents it from taking place.        A system that emits an audible signal when (a) it has reacted to a possible overflow, (b) when the batteries require replacement, and (c) when and if built-in diagnostics determine that it is inoperable.        No aesthetic compromise of the toilet and/or bathroom (device presence and operation are invisible to bathroom occupants).        The batteries reliably operate the unit for a long time (e.g., a minimum of 12 months).        The retail cost to the consumer is below twenty dollars, so that the landed or manufacturing cost (in quantity) of the products can be below four dollars.        Exemplary implementations include original equipment manufacturer version having a overflow prevention and water conservation feature as described herein as part of its normal and intended operation.        